Desktop Viewer installer makes readability assumptions concerning the end user’s appearance settings.
The worst (so far) is assuming a black or dark text color setting, for text superimposed over a graphic.
I use a reverse tone, high contrast scheme with off white text, on charcoal background. This is what the installer dialogs look like:
Basically any text that is going to be superimposed over a graphic should be hardset to a dark color, so as to be always visible.